Moisture is known to condense on skylights, refrigerator/freezer doors, vehicle windows, and other glass products. Condensation buildup on skylights detracts from the aesthetic appeal of the lite. Similarly, condensation buildup on refrigerator/freezer doors in supermarkets or the like sometimes makes it difficult for shoppers to quickly and easily pinpoint the products that they are looking for. And condensation buildup on automobiles often is an annoyance in the morning, as a driver oftentimes must scrape frost or ice and/or actuate the vehicle's defroster and/or windshield wipers to make it safer to drive. Moisture and fog on the windshield oftentimes presents a similar annoyance, although they may also pose potentially more significant safety hazards as a driver traverses hilly areas, as sudden temperature drops occur, etc.
Various anticondensation products have been developed over the years to address these and/or other concerns in a variety of applications. See, for example, U.S. Pat. Nos. 6,818,309; 6,606,833; 6,144,017; 6,052,965; 4,910,088, the entire contents of each of which are hereby incorporated herein by reference. As alluded to above, certain approaches use active heating elements to reduce the buildup of condensation, for example, as in vehicle defrosters, actively heated refrigerator/freezer doors, etc. These active solutions unfortunately take time to work in the vehicle context and thus address the problem once it has occurred. In the case of refrigerator/freezer doors, such active solutions may be expensive and/or energy inefficient.
Some attempts have been made to incorporate a thin-film anticondensation coating on a window. These attempts generally have involved pyrolitically depositing a 4000-6000 angstrom thick fluorine-doped tin oxide (FTO) coating on the exterior surface (e.g., surface 1) of a window such as, for example, a skylight. Although pyrolytic deposition techniques are known to present “hard coatings,” the FTO unfortunately scratches fairly easily, changes color over time, and suffers from other disadvantages.
Thus, it will be appreciated there is a need in the art for articles including improved thin-film anticondensation coatings, and/or methods of making the same.
One aspect of certain example embodiments relates to anticondensation coatings that are suitable for exposure to an external environment, and/or methods of making the same. The external environment in certain example instances may be the outside and/or the inside of a vehicle or house (as opposed to, for example, a more protected area between adjacent substrates).
Another aspect of certain example embodiments relates to anticondensation coatings that have a low sheet resistance and a low hemispherical emissivity such that the glass surface is more likely to retain heat from the interior area, thereby reducing (and sometimes completely eliminating) the presence condensation thereon.
Still another aspect of certain example embodiments relates to coated articles having an anticondensation coating formed on an outer surface and one or more low-E coatings formed on one or more respective interior surfaces of the article. In certain example embodiments, the anticondensation coating may be thermally tempered (e.g., at a temperature of at least 580 degrees C. for at least about 2 minutes, more preferably at least about 5 minutes) or annealed (e.g., at a temperature lower than that required for tempering).
The articles of certain example embodiments may be, for example, skylights, vehicle windows or windshields, IG units, VIG units, refrigerator/freezer doors, and/or the like.
Certain example embodiments of this invention relate to a skylight. First and second substantially parallel, spaced apart glass substrates are provided. plurality of spacers are arranged to help maintain the first and second substrates in substantially parallel, spaced apart relation to one another. An edge seal helps seal together the first and second substrates. An anticondensation coating is provided on an exterior surface of the first substrate exposed to an environment external to the skylight. The anticondensation coating comprises the following thin-film layers deposited in the following order moving away from the first substrate: a silicon-inclusive barrier layer, a first silicon-inclusive contact layer, a layer comprising a transparent conductive oxide (TCO), a second silicon-inclusive contact layer, and a layer of zirconium oxide. The anticondensation coating has a hemispherical emissivity of less than less than 0.23 and a sheet resistance of less than 30 ohms/square.
According to certain example embodiments, a low-E coating is provided on surface 2 and/or 3 of the skylight.
Certain example embodiments of this invention relate to a coated article comprising a coating supported by a substrate. The coating is an anticondensation coating comprising the following thin-film layers deposited in the following order moving away from the first substrate: a silicon-inclusive barrier layer, a first silicon-inclusive contact layer, a layer comprising a transparent conductive oxide (TCO), a second silicon-inclusive contact layer, and a layer of zirconium oxide. The anticondensation coating is disposed on an exterior surface of the substrate such that the anticondensation coating is exposed to an external environment. The anticondensation coating has a hemispherical emissivity of less than less than 0.23 and a sheet resistance of less than 30 ohms/square.
According to certain example embodiments, the external environment is the inside of a house or vehicle. According to certain example embodiments, the external environment is the outside environment. According to certain example embodiments, a low-E coating is provided on the substrate opposite the anticondensation coating.
In certain example embodiments, the coated article may be built into a skylight, window, insulating glass (IG) window, vacuum insulating glass (VIG) window, refrigerator/freezer door, and/or vehicle window or windshield. The anticondensation coating may be provided on surface 1 and/or surface 4 of an IG or VIG unit, for example.
The features, aspects, advantages, and example embodiments described herein may be combined to realize yet further embodiments.